Remove TODO comments about spacing variables (#10695)

The variables on _spacing.pcss have been deprecated by https://github.com/matrix-org/matrix-react-sdk/pull/10686

res/css/views/dialogs/security/_AccessSecretStorageDialog.pcss

@@ -23,7 +23,7 @@ limitations under the License.
             height: 24px;
             margin-inline-end: $spacing-8;
             position: relative;
-            top: 5px; /* TODO: spacing variable */
+            top: 5px;
             background-color: $primary-content;
         }
 
@@ -81,7 +81,7 @@ limitations under the License.
                 mask-repeat: no-repeat;
                 mask-position: center;
                 mask-size: 20px;
-                margin-inline-end: 5px; /* TODO: spacing variable */
+                margin-inline-end: 5px;
             }
 
             &.mx_AccessSecretStorageDialog_recoveryKeyFeedback--valid {
@@ -109,7 +109,7 @@ limitations under the License.
             text-align: initial;
             display: flex;
             flex-flow: column;
-            gap: 14px; /* TODO: spacing variable */
+            gap: 14px;
 
             .mx_Dialog_buttons_additive {
                 float: none;